Saltwater retains about 20% less dissolved oxygen than freshwater at the same pressure and temperature. Does salt water hold less oxygen? Saltwater holds less oxygen than freshwater, so oceanic DO concentrations tend to be lower than those of freshwater. In the ocean, surface water mean annual DO concentrations range from 9 mg/L near the poles…

Gold atoms have a greater mass than iron atoms, so the mass contained in one mole of gold atoms is greater. As an analogy, it’s useful to think of using moles to express amount of substance as being analogous to weighing coin rolls to estimate the number of coins they contain. What is a mole…

German chemist Friedrich Wöhler from ammonium cyanate in 1828 was the first generally accepted laboratory synthesis of a naturally occurring organic compound from inorganic materials. How did organic chemistry start? In the late 1700s and early 1800s, organic natural products were isolated by Scheele, and Chevreuil separated carboxylic acids from saponification of fats. Organic chemistry…

Also Known As: mass percent, (w/w)% mass percent = (mass of element in 1 mole of compound / mass of 1 mole of compound) x 100. mass percent = (grams of solute / grams of solute plus solvent) x 100. How do you find mass percent in a chemical reaction? What is mass percentage of…

1) Write the unbalanced equation. 2) Balance the equation. 3) Indicate the states of matter of the reactants and products. 1) Write the unbalanced equation. 2) Balance the equation. 3) Indicate the physical states of the reactants and products. How do you solve chemical equations for beginners? What are the 4 steps needed to solve…

How do you find the Ksp of a reactant? The equilibrium expression, Ksp, is a ratio of products over reactants and can be written as Ksp = [products]/[reactants]. This expression represents the equilibrium between an ionic solid and its ions in solution. What is a Ksp value in chemistry? The solubility product constant, Ksp​, is…

Neurochemistry of Early Brain Development. The sending and receiving of messages in the nervous system depends on chemical messengers. A number of these chemical messengers affect gene expression in nerve cells in ways that have long-lasting effects on how nerves grow, respond to stimulation, and function. How does brain development affect a child’s behavior? From…

Unlike Botox, too much volume resulting from overuse of facial fillers can be reversed in many cases. Dr. Khosh can use hyaluronidase to precisely target the undesired effects and reverse the impact of too much facial or cheek volume by dissolving the hyaluronic acid gel facial fillers. What are the risk associated with Botox? Possible…

As a common interferer in clinical chemistry, lipemic specimens could be a source of significant analytical errors. Ultracentrifugation has been by far the only reliable, but an unavailable and expensive, method to eliminate the lipemic effect. How does lipemia affect chemistry results? How Does Lipemia Impact Laboratory Testing? Lipemia results from sample turbidity from accumulation…

The nuclear charge is the total charge in the nucleus for all the protons. It has the same value as the number of atoms. Going through the periodic table, the nuclear charge increases. What is nuclear charge equal to? An elements nuclear charge is equal to the number of protons in the nucleus. What is…

Coefficients are used in all chemical equations to show the relative amounts of each substance present. This amount can represent either the relative number of molecules, or the relative number of moles (described below). If no coefficient is shown, a one (1) is assumed. How do coefficients work? Algebra simplifies expressions with coefficients, which are…

Indefatigable despite a career of physically demanding and ultimately fatal work, she discovered polonium and radium, championed the use of radiation in medicine and fundamentally changed our understanding of radioactivity. Curie was born Marya Skłodowska in 1867 in Warsaw. How did Irene Curie contribute to the atomic theory? Scientific Contributions In 1933, the Joliot-Curies made…

The reaction in this activity involves using sodium bicarbonate and citric acid to produce water and carbon dioxide. The tablets contain sodium bicarbonate (NaHCO3) and citric acid. When the tablet is dissolved in water, bicarbonate (HCO3–) and hydrogen ions (H+) are formed. What type of chemical reaction is Alka-Seltzer and water? an Alka-seltzer tablet. Here’s…

Dilution: a process in which the concentration (molarity) of a solution is lowered. The amount of solute (atoms, moles, grams, etc.) remains the same, but the volume is increased by adding more solvent. Stock solution: the more concentrated solution that is used to make the less concentrated solution. How does dilution work in water? Why…

How do you know where to put dashes and wedges? What do wedges and dashes mean in chemistry? Dashed lines show atoms and bonds that go into the page, behind the plane, away from you. In the above example, the OH group is going into the plane, while at the same time a hydrogen comes…

To calculate molar equivalents for each reagent, divide the moles of that reagent by the moles of the limiting reagent: Note that the molar equivalency of sodium benzoate is 1. This is because sodium benzoate is the limiting reagent. Any reagents used in excess will have a molar equivalency greater than one. How do equivalents…

To determine the partial order of O2, note that doubling the concentration of O2 also doubles the rate of the reaction. This may be mathematically expressed as: For the equality to hold true, x must equal 1. This makes the partial order for O2 first order. What is partial order chemistry? The exponents of the…

The oil-loving (hydrophobic) parts stick to the oil and trap oil in the centre. The soap molecules arrange themselves to become a barrier, trapping the oil in the centre. As the soapy water is rinsed away the greasy dirt goes along with it. How does soap work in chemistry? Soap molecules have on one end…

Molecules of just the right chemistry can fit into active sites, much like a key sliding into a lock. Different digestive enzymes are designed to latch onto carbohydrates, proteins or fats. For example, an enzyme in saliva called amylase breaks down starch to form sugars such as glucose. How is chemistry used in nutrition? Chemical…

To prepare aspirin, salicylic acid is reacted with an excess of acetic anhydride. A small amount of a strong acid is used as a catalyst which speeds up the reaction. In this experiment, sulfuric acid will be used as the catalyst. The excess acetic anhydride will be quenched (reacted) with the addition of water. What…